Method for receiving system information in a radio access network, performed by a mobile terminal and mobile terminal for receiving system information in a radio access network

ABSTRACT

A method and transmission apparatus transmit broadcast system information in a mobile communication system. Further, a method and mobile terminal receive the broadcast system information. An improved method for broadcasting broadcast system information maps different partitions of broadcast system information to a shared transport channel or a broadcast transport channel for transmission. The mapping may take into account parameters inherent to the mobile terminals to which the broadcast system information is to be transmitted and/or parameters inherent to the different partitions of broadcast system information.

This is a continuation application of U.S. patent application Ser. No.15/620,276 filed Jun. 12, 2017 (pending), which is a continuation ofU.S. patent application Ser. No. 14/721,378 filed May 26, 2015 (patentedas U.S. Pat. No. 9,713,168), which is a continuation application of U.S.patent application Ser. No. 13/786,098 filed Mar. 5, 2013 (patented asU.S. Pat. No. 9,066,339), which is a continuation application of U.S.patent application Ser. No. 12/094,267 filed Nov. 18, 2008 (patented asU.S. Pat. No. 8,412,211), which is a national stage of PCT/EP2006/010153filed Oct. 20, 2006, which is based on European Application No.05027214.5 filed Dec. 13, 2005, the entire contents of each of which areincorporated by reference herein.

FIELD OF THE INVENTION

The present invention relates to a method and transmission apparatus fortransmitting broadcast system information in a mobile communicationsystem. Further, the invention relates to a method and mobile terminalreceiving the broadcast system information.

TECHNICAL BACKGROUND

W-CDMA (Wideband Code Division Multiple Access) is a radio interface forIMT-2000 system (International Mobile Telecommunication system), whichwas standardized for use as the 3.sup.rd generation wireless mobiletelecommunication system. It provides a variety of services such asvoice services and multimedia mobile communication services in aflexible and efficient way. The standardization bodies in Japan, Europe,USA, and other countries have jointly organized a project called the3^(rd) Generation Partnership Project (3GPP) to produce common radiointerface specifications for W-CDMA.

The standardized European version of IMT-2000 is commonly called UMTS(Universal Mobile Telecommunication System). The first release of thespecification of UMTS has been published in 1999 (Release 99). In themean time several improvements to the standard have been standardized bythe 3GPP in Release 4, Release 5 and Release 6. A discussion on furtherimprovements is ongoing under the scope of Release 7 and Study Item onEvolved UTRA and UTRAN.

UMTS Architecture

The high level Release 99/4/5 architecture of Universal MobileTelecommunication System (UMTS) is shown in FIG. 1 (see 3GPP TR 25.401:“UTRAN Overall Description”, incorporated herein by reference, availablefrom http://www.3gpp.org). The UMTS system consists of a number ofnetwork elements each having a defined function. Though the networkelements are defined by their respective function, a similar physicalimplementation of the network elements is common but not mandatory.

The network elements are functionally grouped into the Core Network (CN)101, the UMTS Terrestrial Radio Access Network (UTRAN) 102 and the UserEquipment (UE) 103. The UTRAN 102 is responsible for handling allradio-related functionality, while the CN 101 is responsible for routingcalls and data connections to external networks. The interconnections ofthese network elements are defined by open interfaces (Iu, Uu). Itshould be noted that UMTS system is modular and it is therefore possibleto have several network elements of the same type.

In the sequel two different architectures will be discussed. They aredefined with respect to logical distribution of functions across networkelements. In actual network deployment, each architecture may havedifferent physical realizations meaning that two or more networkelements may be combined into a single physical node.

FIG. 2 illustrates the current architecture of UTRAN. A number of RadioNetwork Controllers (RNCs) 201, 202 are connected to the CN 101.Functionally, the RNC 201, 202 owns and controls the radio resources inits domain and typically terminates the Radio Resource Control protocolon the access network side. Each RNC 201, 202 controls one or severalbase stations (Node Bs) 203, 204, 205, 206, which in turn communicatewith the user equipments. An RNC controlling several base stations iscalled Controlling RNC (C-RNC) for these base stations. A set ofcontrolled base stations accompanied by their C-RNC is referred to asRadio Network Subsystem (RNS) 207, 208. For each connection between UserEquipment and the UTRAN, one RNS is the Serving RNS (S-RNS). Itmaintains the so-called Iu connection with the Core Network (CN) 101.When required, the Drift RNS 302 (D-RNS) 302 supports the Serving RNS(S-RNS) 301 by providing radio resources as shown in FIG. 3. RespectiveRNCs are called Serving RNC (S-RNC) and Drift RNC (D-RNC). It is alsopossible and often the case that C-RNC and D-RNC are identical andtherefore abbreviations S-RNC or RNC are used. Commonly, a Drift RNS 302is used for soft handovers of UEs between different RNS.

General Description of the Protocol Model of the UTRAN TerrestrialInterfaces

FIG. 4 shows an overview of the protocol model of the UTRAN in an UMTSnetwork. For a better understanding, only a brief description isprovided herein; further details may be found in Holma et al., “WCDMAfor UMTS”, Third Edition, Wiley & Sons, Inc., October 2004, Chapter 5,incorporated herein by reference.

On the horizontal plane, the protocol model can be split into the radionetwork layer and the transport network layer. All UTRAN-related issuesare visible and handled on the radio network layer, while transportnetwork layer typically represents standard transport technology that isselected to be used for data transport for the UTRAN without anyUTRAN-specific changes.

On the vertical plane, the protocol model can be split into controlplane and user plane. The control plane is used for UMTS-specificcontrol signaling (i.e. signaling related to radio and transportinterfaces) and includes the Application Protocol (AP), e.g. RANAP onthe Iu interfaces, RNSAP on the Iur interfaces, NBAP on the Iub and RRCon Uu interfaces. The control plane functions and Application Protocolallows setting up traffic radio bearers to the UEs via so-calledsignaling radio bearers.

While the control plane protocols are responsible for the UNITS-specificcontrol signaling, the user plane transports the data streams sent byand sent to the users, such as voice calls, streaming data, packets ofpacket-switched services, etc. For transport, the user plane containsthe so-called traffic radio bearers (also sometimes referred to as DataBearers).

The transport network control plane is used for control signaling withinthe transport network layer and does not include any radio network layerrelated information. The transport network control plane includes theALCAP protocol, which is used to set up the traffic bearers forexchanging user plane information and the signaling bearers required forcommunicating ALCAP protocol messages. Due to the presence of thetransport network control plane, it is possible that the ApplicationProtocol within the control plane may operate completely independentfrom the technology selected for data transport on the traffic radiobearers in the user plane. The transport network control plane controlsthe operation of the transport network user plane.

UTRA Radio Interface Protocol Architecture

An overview of the radio interface protocol architecture of the UTRAN isshown in FIG. 5. Generally, the radio interface protocol architecture ofthe UTRAN implements Layers 1 to 3 of the OSI protocol stack. Theprotocols terminated in the UTRAN are also referred to as the accessstratum (protocols). In contrast to the access stratum, all protocolsnot terminated in the UTRAN are typically also referred to as thenon-access stratum protocols.

As has been discussed with respect to FIG. 4, the vertical split of theprotocols into user plane and control plane is illustrated. The RadioResource Control (RRC) protocol is a Layer 3 protocol of the controlplane which controls the protocols in the lower layers of the UTRA RadioInterface (Uu).

The RRC protocol is typically terminated in the RNC of the UTRAN,however other network elements have also been considered for terminatingthe RRC protocol in the UTRAN, e.g. the Node Bs. The RRC protocol isused for signaling of control information to control access to radioresources of the radio interface to the UEs. Further, there is also thepossibility that the RRC protocol encapsulates and transports non-accessstratum messages, which are usually related to control within thenon-access stratum.

In the control plane, the RRC protocol relays the control information toLayer 2, i.e. the Radio Link Control (RLC) protocol, via signaling radiobearers through Service Access Points (SAPs). In the user plane thenon-access stratum protocol entities may use traffic radio bearers todirectly access Layer 2 via SAPs. The access may be made to the RLCdirectly or to the Packed Data Convergence Protocol which in turnprovides its PDUs to the RLC protocol entity.

The RLC offers the SAPs to the higher layers. The RRC configurationdefines how RLC will handle the packets, e.g. whether RLC is operatingin transparent, acknowledged or unacknowledged mode. The serviceprovided to the higher layers in the control plane and user plane by theRRC or PDCP are also referred to as signaling radio bearer and trafficradio bearer, respectively.

The MAC/RLC layer in turn offers its services to the RLC layer by meansof so-called logical channels. The logical channels essentially definewhat kind of data is transported. The physical layer offers its servicesto the MAC/RLC layer, the so-called transport channels. The transportchannels define how and with which characteristics the data receivedfrom the MAC layer are transmitted via the physical channels.

Logical and Transport Channels in UTRAN

In this section the mapping between logical channels and transportchannels will be outlined referring for exemplary purposes to the UNITSarchitecture. The mapping of logical channels to transport channels maybe utilized for some of the signaling messages within a RRC connectionestablishment procedure.

The characteristics and mapping of logical and transport channels forUTRA and E-UTRA are summarized in the following tables. Logical channelsare mainly described by data type to be transmitted whereas transportchannels are mainly described by respective transmission types andidentification method.

The table below contains a description of logical and transport channelsfor UTRA and E-UTRA, respectively.

TABLE 1 Logical (LCH) or Transport Channel characteristic Channel (TrCH)Direction: type vs. channel Uplink (UL) Mapping characteristic DataTransmission or Downlink Identification (LCH −> and mapping Type Type(DL) method TrCH) LCH BCCH system N/A DL N/A BCCH −> (Broadcastinformation BCH Control (broadcast) CHannel) CCCH common N/A UL or DLN/A, Note: this CCCH −> (Common service logical channel is FACH, Controlcontrol mainly used for RACH CHannel) (unicast) transmission of controlplane information prior to identifier assignment to UE by radio accessnetwork DCCH dedicated N/A UL or DL N/A DCCH −> (Dedicated service FACH,Control control RACH, CHannel) (unicast) DCH TrCH BCH N/A Common DL N/Adue to N/A (Broadcast channel with broadcast data CHannel) static typeconfiguration FACH N/A Common DL Layer 2 inband N/A (Forward channelwith when carrying Access semi-static DCCH, N/A CHannel) configurationotherwise RACH N/A Common UL Layer 2 inband N/A (Random channel withwhen carrying Access semi-static DCCH, N/A CHannel) configurationotherwise and contention- based access DCH N/A Dedicated UL or DL N/Asince this is N/A (Dedicated channel with dedicated CHannel) semi-statictransport channel configuration

Please note that mapping of DCCH in the table above may be possible on aFractional Dedicated Channel in downlink direction for UMTS Release 6and on Enhanced Dedicated Transport Channel in uplink for UMTS Release 6of the Evolved UTRA. These options have however not been considered inthe table for the sake of simplicity.

For UTRA, identification of transport channels as shown in the tableabove is Layer 2 inband. Layer 2 inband identification means that headerof a Layer 2 MAC PDU contains UE identifier pointing at a specific UE asa destination or source of information for downlink or uplink direction,respectively. Consequently, for mapping of logical channels containingdata of system information and common service control typeidentification is not needed. Identification is applicable only tocommon transport channels (RACH and FACH) apart from broadcast commontransport channel (BCH).

The following table shows an exemplary description of logical channelsand transport channels in the Evolved UTRA (E-UTRA).

TABLE 2 Logical (LCH or Transport Channel characteristic Channel (TrCH)Direction: type vs. channel Uplink (UL) Mapping characteristic DataTransmission or Downlink Identification (LCH −> and mapping Type Type(DL) method TrCH) LCH BCCH system N/A DL N/A BCCH −> (Broadcastinformation Evolved- Control (broadcast) BCH CHannel) CCCH common N/A ULor DL N/A, Note: this CCCH −> (Common service logical channel SDCH (inControl control is mainly used downlink CHannel) (unicast) fortransmission direction of control plane only), CACH information prior toidentifier assignment to UE by radio access network DCCH dedicated N/AUL or DL N/A DCCH −> (Dedicated service SDCH, Control control SUCHCHannel) (unicast) TrCH Evolved-BCH N/A Common DL N/A due to N/A(Evolved channel broadcast data Broadcast with static type CHannel)configuration CACH N/A Common UL Layer 2 inband N/A (Contention channelwith when carrying Access semi-static DCCH, N/A CHannel) configurationand otherwise contention-based access SDCH N/A Shared DL Layer 1 N/A(Shared channel with outband Downlink dynamic configuration CHannel) andscheduled access SUCH N/A Dedicated UL Layer 1 N/A (Shared channel withoutband Uplink semi-static CHannel) configuration

It can be noted that legacy EACH is not used and that shared channelsare used instead of legacy DCH. It is assumed that associated physicalchannels in downlink direction are used for both SDCH and SUCH. Anexample of associated physical channel could be Shared Control SignalingCHannel (SCSCH).

The transmission types description in the respective column of the tableabove should be understood as follows. A static configuration means thatthe transport format attributes of the channel, e.g. modulation, forwarderror correction scheme etc. are system-specific and are not subject tochange by the network. In a semi-static configuration the transportformat attributes of the channel, e.g. modulation, forward errorcorrection scheme etc. are subject to change by reconfigurationprocedure. The procedure is fairly slow introducing latency of the orderof 100 ms. Finally, in a dynamic configuration the transport formatattributes of the channel, e.g. modulation, forward error correctionscheme etc. are subject to change by signaling on associated controlchannels. The procedure is fairly fast relative to semi-staticreconfiguration and may introduce a delay of the order of severalsub-frames (1 sub-frame˜0.5 ms). Dynamic configuration may be carriedout so as to optimally match transmission format to temporal variationsof radio channel in which case it may be referred to as link adaptation.

Information that may be transmitted by this channel is given in thetable below:

TABLE 3 Control signaling Control signaling for downlink for uplinkPhysical Demodulation Transmission power control bits control Chunkallocation Transmission timing control bits information ACK/NACK bit forthe reservation Data modulation channel and fast access channelTransport block size L2 Scheduling Scheduling control UE identity UEidentity H-ARQ Chunk allocation information H-ARQ process Datamodulation information Transport block size Redundancy version H-ARQ Newdata indicator ACK/NACK

It can be seen from the table that UE identification information iscontained in both downlink and uplink directions. Thus, by virtue ofLayer 1 outband identification, having decoded the data on the SCSCH andhaving determined that the identifier transmitted on the associatedphysical channel corresponds to the identifier assigned to the UE duringthe RRC connection establishment procedure, the UE can receive physicalchannels on which respective shared transport channels are mapped andfurther process Layer 2 PDUs (Protocol Data Units) corresponding to SDCHand SUCH shared transport channels. Identification for CACH transportchannel is analogous to the identification for RACH transport channel inE-UTRA. It can be concluded that identification is applicable to commonand shared transport channels (CACH, SDCH and SUCH) apart from evolvedbroadcast common transport channel (Evolved-BCH). Identification forsaid common transport channels is of L2 inband type, while theidentification for shared transport channels is of Layer 1 outband type.

From the definitions of “Layer 2 inband” and “Layer 1 outband”identification one could infer that there is one and only one identifierper UE. Hence, once a Signaling Radio Bearer has been established, theUE has been assigned identifier that can be used for Traffic RadioBearer as well. However, it is possible that multiple identifiers per UEare defined and used per configured transport channel.

Spectrum Allocation

With respect to stand-alone operation of the mobile terminals spectrumallocations of different sizes (e.g. 1.25 MHz, 2.50 MHz, 5.00 MHz, 10.00MHz, 15.00 MHz and 20.00 MHz) have been suggested in 3GPP TR 25.912,“Requirements for Evolved UTRA (E-UTRA) and Evolved UTRAN (E-UTRAN)”,version 7.1.0 (available at http://www.3gpp.org). It can be shown thatdata rate of evolved Primary Common Control Physical Channel (P-CCPCH—inlegacy system, the BCH transport channel is mapped to the P-CCPCH)varies depending on size of spectrum allocation (as indicated in thetable below), assuming that configuration of Evolved Broadcast TransportChannel is semi-static.

TABLE 4 [MHz] 1.25 2.50 5.00 10.00 15.00 20.00 [kbps] 4.00 8.00 16.0032.00 48.00 64.00,

It can concluded that the UE reading time for reading a predeterminedamount of data from the physical channels depends upon spectrumallocation. Therefore, for smaller spectrum allocations, the UE readingtime and thereby power consumption is increased. Furthermore, when thedata size implies the transmission of the data over several transmissiontime intervals (TTIs), the UE has to power its receiver to receive dataat all TTIs in which the data is provided. For larger spectrumallocations, the UE reading time is decreased, but if several dataportions are sent in one TTI, UE may need to decode irrelevant portionsin that TTI, since the receivers may typically only be tuned to receivedata of a complete TTI. This may also lead to unnecessarily increased UEpower consumption.

The potential shortcomings outlined above are illustrated in FIGS. 8 and9 for the transmission of broadcast system information (BSI), which istypically partitioned into system information blocks (SIBs) in UMTS(FIG. 7). From FIG. 8, it can be recognized that for a spectrumallocation size of 5.00 MHz, the UE has to receive contents of thebroadcast control channel BCCH over two successive TTIs to acquireinformation contained in SIB8, even though possibly MIB (at a given timeinstant) and SIB719/10 may not be of interest for the UE. Also, forlarger spectrum allocations, e.g. of the size 10.00 MHz, as shown inFIG. 4, the UE decodes the master information block MIB and SIB1. Inaddition, the UE also decodes SIB2 and SIB3 even though the contents ofthese information blocks may not be necessary for system access orelementary mobility functions

SUMMARY OF THE INVENTION

The object of the invention is to suggest an improved method forbroadcasting broadcast system information.

The object is solved by the subject matter of the independent claims.Advantageous embodiments of the invention are subject matters to thedependent claims.

According to an aspect of the invention, different partitions ofbroadcast system information are mapped to a shared transport channel ora broadcast transport channel for transmission. According to anembodiment of the invention, the mapping may take into accountparameters inherent to the mobile terminals to which the broadcastsystem information is to be transmitted and/or parameters inherent tothe different partitions of broadcast system information.

In an embodiment of the invention, a method for transmitting broadcastsystem information in a radio access network of a mobile communicationsystem is provided. According to the method, system information blocksof a broadcast control logical channel is mapped to a shared transportchannel or a broadcast transport channel depending on a property of arespective system information block or the mobile terminals to receivethe broadcast system information, and the system information blocks aretransmitted via the shared transport channel and the broadcast transportchannel, respectively.

In an embodiment of the invention, a method for transmitting broadcastsystem information in a radio access network of a mobile communicationsystem is provided. According to the method, system information blocksof a broadcast control logical channel is mapped to a shared transportchannel or a broadcast transport channel depending on a property of arespective system information block or the mobile terminals to receivethe broadcast system information, and the system information blocks aretransmitted via the shared transport channel and the broadcast transportchannel, respectively.

Examples for an intrinsic property of the mobile terminals may be acapability to support an optional feature within the mobilecommunication system.

In another embodiment of the invention, a master information block of abroadcast control logical channel is transmitted periodically via thebroadcast transport channel. The master information block may comprisecontrol information associated to a respective one of the systeminformation blocks. The associated control information may indicatewhether a respective system information block is mapped to the broadcasttransport channel or the shared transport channel.

In case a system information block is mapped to the shared transportchannel, in a variation of the embodiment, the associated controlinformation comprises transmission format and timing of a respectivesystem information block transmitted via the shared transport channel.

In a further variation, the associated control information specifies atleast the position of the respective system information block on thebroadcast transport channel, the time interval at which the respectivesystem information block is transmitted and a timer value- or valuetag-based update mechanism to be utilized to update the information ofthe respective system information block,

In a further embodiment of the invention the control information istransmitted on a control channel associated to the shared data channel.The control information may indicate to the transmission format andtiming of a respective system information block transmitted via theshared transport channel.

In a variation of the embodiment, the control information furthercomprises identification of the logical channel-to-transport channelmapping.

In a variation of the embodiment, the control information furthercomprises identification of the logical channel-to-transport channelmapping.

In both embodiments above, the identification of the logicalchannel-to-transport channel mapping may be made by including aplurality of configured or default identifiers to the controlinformation as transmitted on master information block.

In a further embodiment of the invention the system broadcastinformation comprises information on the configuration of at least oneshared transport channel of a neighboring radio cell.

Another embodiment of the invention relates to the reception ofbroadcast system information in a radio access network of a mobilecommunication system by a mobile terminal. The mobile terminal mayreceive a master information block of a broadcast control logicalchannel via a broadcast transport channel. The master information blockmay comprise control information associated to a respective one of aplurality of system information blocks used to convey the broadcastsystem information. Further, the associated control information mayindicate to the mobile terminal whether a respective system informationblock of a plurality of system information blocks conveying thebroadcast system information is mapped to the broadcast transportchannel or a shared transport channel. The mobile terminal may receivesystem information blocks of a broadcast control logical channel on ashared transport channel or a broadcast transport channel according tothe indication in the master information block.

In case a system information block is to be received via the sharedtransport channel, a variation of the embodiment foresees comprising aconfiguration of the shared transport channel to which the systeminformation block is mapped, further associated control information inthe master information block, and identifying the shared transportchannel on which the system information block is mapped among aplurality of shared transport channels based on the indication in theassociated control information of the master information block toreceive the system information block via the identified shared channeland transmitted configured or default identifier. The configuration mayfor example be a set of transmission format parameters. The indicationof the mapping of individual SIBs to the shared transport channel mayfor example be made by using configured or default identifiers, eachidentifying an associated transport channel in the system.

In another embodiment of the invention the mobile terminal may receivecontrol information on a physical control channel associated to theshared data channel. The associated control information may indicate thetransmission format and timing of a respective system information blocktransmitted via the shared transport channel. The mobile terminal mayutilize the indicated transmission format and timing for receiving therespective system information block via the shared transport channel.

Further, in an embodiment of the invention, the system broadcastinformation received by the mobile terminal may also compriseinformation on the configuration of at least one shared transportchannel of a neighboring radio cell and the mobile terminal may use theinformation on the configuration of at least one shared transportchannel of a neighboring radio cell for receiving broadcast systeminformation in the neighboring radio cell, in case the mobile terminalis handed over to the neighboring radio cell.

Another embodiment of the invention provides a transmission apparatus ina radio access network for transmitting broadcast system information inthe radio access network of a mobile communication system. Thetransmission apparatus may comprise a processor to map systeminformation blocks of a broadcast control logical channel to a sharedtransport channel and a broadcast transport channel depending on aproperty of a respective system information block or the mobileterminals to receive the broadcast system information. Further, it maycomprise a transmitter to transmit the system information blocks via theshared transport channel and the broadcast transport channel,respectively.

In a variation of the embodiment, the transmission apparatus isconfigured to perform the steps of the method for transmitting broadcastsystem information according to one of the various embodiments andvariations described herein.

A further embodiment of the invention relates to a mobile terminal forreceiving broadcast system information in a radio access network of amobile communication system. According to this exemplary embodiment themobile terminal comprises a receiver for receiving a master informationblock of a broadcast control logical channel via a broadcast transportchannel. Moreover, the mobile terminal may be configured with aprocessor for obtaining control information from the master informationblock. This control information is associated to a respective one of aplurality of system information blocks used to convey the broadcastsystem information and may indicate whether a respective systeminformation block is mapped to the broadcast transport channel or ashared transport channel. The receiver may further receive systeminformation blocks of a broadcast control logical channel on a sharedtransport channel or a broadcast transport channel according to theindication in the master information block.

The mobile terminal according to another embodiment of the invention maybe configured to perform the steps of the method for receiving broadcastsystem information according to one of the different embodiments andvariations described herein.

Other embodiment of the invention relates to the implementation of thedifferent aspects of the invention in software. Therefore, an embodimentof the invention provides a computer-readable medium storinginstructions that, when executed by a processor of a transmissionapparatus, causes the transmission apparatus to transmit broadcastsystem information in a radio access network of a mobile communicationsystem. In this embodiment, the transmission apparatus is caused totransmit broadcast system information by mapping system informationblocks of a broadcast control logical channel to a shared transportchannel or a broadcast transport channel depending on a property of arespective system information block or the mobile terminals to receivethe broadcast system information, and by transmitting the systeminformation blocks via the shared transport channel and the broadcasttransport channel, respectively.

The computer-readable medium according to another embodiment of theinvention may further store instructions that cause the processor of thetransmission apparatus to execute the steps of the method fortransmitting broadcast system information according to one of theembodiments and variants described herein.

A further embodiment of the invention provides a computer-readablemedium storing instructions that, when executed by a processor of amobile terminal, causes the mobile terminal to receive broadcast systeminformation in a radio access network of a mobile communication system.

The mobile terminal may be caused to receive broadcast systeminformation by receiving a master information block of a broadcastcontrol logical channel via a broadcast transport channel and byreceiving system information blocks of a broadcast control logicalchannel on a shared transport channel or a broadcast transport channelaccording to the indication in the master information block. The masterinformation block may comprise control information associated to arespective one of a plurality of system information blocks used toconvey the broadcast system information. The associated controlinformation indicates whether a respective system information block ismapped to the broadcast transport channel or a shared transport channel.

The computer-readable medium in another embodiment of the inventionfurther stores instructions causing the processor of the mobile terminalto execute the steps of the method for receiving broadcast systeminformation according to one of the various embodiment and variantsthereof described herein.

BRIEF DESCRIPTION OF THE FIGURES

In the following the invention is described in more detail in referenceto the attached figures and drawings. Similar or corresponding detailsin the figures are marked with the same reference numerals.

FIG. 1 shows the high-level architecture of UMTS,

FIG. 2 shows the architecture of the UTRAN according to UMTS R99/415,

FIG. 3 shows a Drift and a Serving Radio Subsystem in a UNITS network,

FIG. 4 shows an overview of the protocol model of the UTRAN in an UMTSnetwork,

FIG. 5 shows an overview of the radio interface protocol architecture ofthe UTRAN,

FIG. 6 shows the structure of a Master Information Block (MIB),

FIGS. 7 to 9 show examples of transmissions of Broadcast SystemInformation (BSI) in System Information Blocks (SIBs) at different usingdifferent channel bandwidths,

FIG. 10 shows an exemplary mapping of system information blocks ofbroadcast system information to a broadcast transport channel and ashared transport channel using Layer 1 outband identification accordingto an embodiment of the invention,

FIG. 11 shows an exemplary format of a Master Information Block used inthe mapping of system information blocks in FIG. 10 according to anembodiment of the invention,

FIG. 12 shows an exemplary mapping of system information blocks ofbroadcast system information to a broadcast transport channel and ashared transport channel using Layer 2 inband identification accordingto an embodiment of the invention,

FIG. 13 shows an exemplary format of a Master Information Block used inthe mapping of system information blocks in FIG. 12 according to anembodiment of the invention,

FIGS. 14 to 17 show different examples of mapping of system informationblocks to a shared transport channel and a broadcast transport channelbased on different criteria according to different embodiments of theinvention, and

FIG. 18 shows a mapping of system information blocks of broadcast systeminformation comprising information on a shared transport channel in aneighboring radio cell to a broadcast transport channel and a sharedtransport channel and a handover of a mobile terminal to the neighboringradio cell according to an embodiment of the invention.

DETAILED DESCRIPTION OF THE INVENTION

The following paragraphs will describe various embodiments of theinvention. For exemplary purposes only, most of the embodiments areoutlined in relation to a UMTS communication system and the terminologyused in the subsequent sections mainly relates to the UMTS terminology,as the invention may be advantageously used in this type ofcommunication system. However, the terminology used and the descriptionof the embodiments with respect to a UMTS system is not intended tolimit the principles and ideas of the invention to such system.

Also the detailed explanations given in the Technical Background sectionabove are intended to better understand the mostly UNITS specificexemplary embodiments described in the following and should not beunderstood as limiting general ideas underlying the invention to thedescribed specific implementations of processes and functions in amobile communication network.

According to one aspect of the invention, it is proposed to mapbroadcast system information of logical channels to a shared transportchannel and/or to a broadcast transport channel. Broadcast systeminformation may for example be information transmitted over a broadcastcontrol logical channel.

In an embodiment of the invention, the mapping of different portions ofthe broadcast system information, also referred to as system informationblocks herein, to either one of the two transport channels is based on acertain criterion or certain criteria. For example, criteria that may beused as a basis for the mapping decision may be intrinsic property of asystem information block or an intrinsic property of the mobileterminals to which the system information is to be broadcast.

Examples for an intrinsic property of a system information block may betemporal variability of the information contained in the systeminformation block or the size of the system information block. Anotherintrinsic property of a system information block is for example thenecessity of the information comprised in the system information blockfor system access or the necessity of the information comprised in thesystem information block for tracking user location within the mobilecommunication system.

An intrinsic property of the mobile terminals may for example be thecapability of terminals to support feature(s) defined optional withinthe mobile communication system.

The mapping of system information blocks to a shared or broadcasttransport channel can be advantageous in that the acquisition of thisinformation by mobile terminals in terms of terminal processing time andpower consumption may be optimized. Other advantages that may beachieved when applying the invention may be improved reading time forbroadcast system information of mobile terminals for all sizes ofstandalone spectrum allocations, greater flexibility of operators inconfiguring transport channels for broadcast and increased schedulingefficiency of system information, which may be a result from mappingsystem information to a shared transport channel.

Another aspect of the invention is the behavior of the mobile terminalsto receive the broadcast system information. According to anotherembodiment of the invention, the mobile terminals will receive a masterinformation block on the broadcast transport channel, which indicatesthe mapping of individual SIBs to either the broadcast transport channelor the shared transport channel. Based on the indication of the mappingused, the mobile terminals will receive the SIBs either on the broadcastcontrol channel or the shared control channel. In another embodiment ofthe invention, Layer 1 outband or Layer 2 inband identification is usedfor providing the mobile terminals with control information necessary toappropriately receive the SIBs, as will be outlined in more detailbelow.

In the following the structure of system broadcast information and theirallocation to different System Information Blocks (SIBs) according to anexemplary embodiment of the invention is outlined considering a UNITSsystem. The structure of the information transmitted on the broadcastcontrol channel—a logical channel—may be tree-like. A so-called MasterInformation Block (MIB) forms the root of the tree structure, whereasthe so-called System Information Blocks (SIBs) represent its branches.The MIB information may be transmitted less frequently than the SIBscarrying the broadcast system information. The information in the MIBmay also not need to be read by the individual terminals each time theMIB information is transmitted.

The structure of the information on the BCCH is shown for exemplarypurpose in FIG. 6. One part of MIB may for example be reserved forinformation upon each System Information Block. The control informationassociated to a respective SIB and comprised in the reserved parts mayhave the following structure. Each control information associated to aSIB may indicate the position of SIB on the broadcast transport channelon which it is transmitted relative to common timing reference. Further,a repetition period of SIB may be indicated. This repetition periodindicates the periodicity at which the respective SIB is transmitted.The control information may further include a timer value fortimer-based update mechanism or, alternatively, a value tag fortag-based update of the SIB information.

For SIBs whose reference in MIB contains timer value, a mobile terminalmay update system information after expiry of value indicated in timerfield of MIB. For SIBs whose reference in MIB contains value tag, amobile terminal may update system information after the value of tag asindicated in respective field of MIB has been changed with respect tothe value from the previous update. Respective exemplary MIB formatsaccording to different embodiments of the invention will be describedwith reference to FIGS. 11 and 13 below.

The table below shows an exemplary overview of the categorization andtypes of system information blocks in an UMTS legacy system (see 3GPP TS25.331, “Radio Resource Control (RRC)”, version 6.7.0, section 8.1.1,incorporated herein by reference; available at http://www.3gpp.org) thatmay be used in the different embodiments of the invention describedherein. In this example, the classification of the system broadcastinformation into the different SIBs is based on the content and temporalvariability.

TABLE 5 Temporal SIB Content Variability SIB1 NAS info, UEtimers/counters low SIB2 URA identity low SIB3 Cell selection parameterslow SIB4 Cell selection par. for connected mode low SIB5 Common physicalchannels configuration medium SIB6 Common physical channelsconfiguration medium SIB7 Interference/dynamic persistence level highSIB11 Measurement control medium SIB12 Measurement control informationfor connected medium mode SIB13 ANSI-41 info low SIB14 Outer loop powercontrol information medium SIB15 Positioning information low SIB16Preconfiguration medium SIB17 Configuration of shared physical channelsin high connected mode SIB18 PLMN IDs of neighboring cells low

The contents of the table illustrated above should be only considered asone possible example of the contents and classification of the broadcastsystem information. Also the classification of the frequency at whichthe different portions of the system information is broadcast and itsclassification into the different SIBs is intended to serve only forexemplary purposes and is not intended to limit the invention to thisexample. It is recognized that in the ongoing development andimprovement of existing mobile communication systems, the content,format, periodicity of transmission, etc. may change.

FIG. 10 shows an exemplary mapping of system information blocks ofbroadcast system information to a broadcast transport channel and ashared transport channel using Layer 1 outband identification accordingto an embodiment of the invention. In FIG. 10, the data mapped to threedifferent channels, a broadcast transport channel, a shared transportchannel and a physical control channel associated to the sharedtransport channel, is shown. The control channel is associated to theshared transport channel in that it contains control informationdescribing transmission format and timing of the data on the sharedtransport channel. In another embodiment of the invention the parametersdescribing transmission format may define the format for an OFDMA basedradio access as described in Tdoc R1-050604 of the 3GPP TSG RAN WG #1 adhoc, “Downlink Channelization and Multiplexing for EUTRA”, June 2005(available at http://www.3gpp.org), incorporated herein by reference).

Further, the mobile terminal (or, equivalently, logical to transportchannel mapping) to receive the system information may be designated byrespective Layer 1 outband identification as discussed previously.Accordingly, the logical-to-transport channel mapping is indicated onthe associated physical control channel (e.g. SCSCH),

The broadcast system information provided on the broadcast controllogical channel (e.g. the BCCH in UMTS), is mapped to the sharedtransport channel and the broadcast transport channel of FIG. 10.

For the broadcast transport channel, three transport blocks are shown inFIG. 10. In the exemplary embodiment, a Master Information Block (MIB)is transmitted periodically (MIB repetition period). For example, theMIB may be transmitted at the beginning of each transport block or aftera predetermined time span, such as a given number of transmission timeintervals (TTIs). Further, a transport block may comprise one or moreSystem Information Blocks (SIBs). A SIB comprises a portion of thesystem broadcast information to be transmitted. For example, each SIBmay comprise a predetermined or configurable set of information of acertain category as exemplified in the Table 5.

The MIB used in the exemplary embodiment shown in FIG. 10 is illustratedin FIG. 11 in further detail. The structure of system broadcastinformation according to this embodiment of the invention is alsotree-like, as has been outlined above. The MIB comprises differentpartitions of control information each of these partitions beingassociated to a respective SIB.

For those SIBs that are mapped to the broadcast transport channel fortransmission, the control information associated to a respective SIB mayhave the following structure. Each control information associated to aSIB (pointer to SIB #n) indicates the position of the SIB on thebroadcast transport channel on which it is transmitted relative tocommon timing reference. Further, a repetition period of SIB indicatingthe periodicity at which the respective SIB is transmitted may beindicated. In the exemplary embodiment shown in FIG. 10, the controlinformation in the MIB associated to SIB1, SIB3, SIB 4 and SIB6 havethis structure.

In contrast to SIB1, SIB3, SIB 4 and SIB6, SIB2 is transmitted via theshared transport channel. The MIB control information relating to SIB2has a different structure than the control information for the set ofSIBs. According to the exemplary embodiment, the control information forSIB2 in the MIB comprises an indication of the shared transport channelon which SIB2 is transmitted. This indication is illustrated by thedashed arrow pointing from the MIB to the shared transport channel inFIG. 10.

Based on the control information in the MIB, the mobile terminals mayrecognize which SIBs are transmitted and to which channel they aremapped. I.e. in the exemplary embodiment, the mobile terminals determinethat SIB1, SIB3, SIB4 and SIB6 are mapped to and transmitted on thebroadcast transport channel, while SIB2 is mapped to and transmitted onthe shared transport channel.

As indicated above, Layer 1 outband identification is used forindicating the logical channel-to-transport channel mapping to thereceiving mobile terminals. For this purpose and identification of themapping is transmitted on the associated control channel (see “ID”).This identification may for example use default or configuredidentifiers of the logical channel to which a respective transportchannel is to be mapped on the receiving side. These identifiers may betransmitted by in the MIB.

The identifiers may for example be HEX-values:

-   -   0x0000 00FF logical channel BCCH (Broadcast Control Channel) is        mapped upon SUCH,    -   0x0100 01FF logical channel PCCH (Paging Control Channel) is        mapped upon SUCH and    -   0x0200 FFFF logical channel DCCHIDTCH (Dedicated Control        Channel/Dedicated Transport Channel) is mapped upon SUCH

The identifiers used may be default values or may be configured by thesystem.

The control channel associated to the shared transport channel comprisescontrol information, which indicates the scheduling of the SIB on theshared transport channel. The control information may at least indicatetemporal position of the SIB(s) mapped to the shared channel on thatchannel for a respective SIB. In another embodiment of the invention thecontrol information on the associated control channel is schedulinginformation as shown in Table 3 above and may comprise information onchunk allocation, data modulation and transport block size. According toan embodiment of the invention the transmission format parameters may bedefined as in Tdoc R1-050604 3GPP TSG RAN WG1 ad hoc “DownlinkChannelisation and Multiplexing for EUTRA”. mentioned above,

Hence, in the exemplary embodiment shown in FIG. 10, the MIB controlinformation indicate to the mobile terminal that SIB2 has been mapped tothe shared transport channel, while the control information for SIB onthe associated control channel indicates the temporal position of SIB2on the shared channel to a receiving mobile terminal and transmissionformat.

According to one embodiment of the invention, the temporal position canbe given as dynamically changing scheduling information with respect tocommon system timing reference. An exemplary implementation is forexample described in the TS 25.331 “Radio Resource Control (RRC)”mentioned above. As explained above, the transmission format mayindicate at least chunk allocation, data modulation and transport blocksize. Finally, although not explicitly mentioned, a configuration of theassociated physical control channel (e.g. SCSCH) may also be necessary.

Returning to the transmission of broadcast system information in UMTSsystems for exemplary purposes only, Layer 1 outband identification andtransmission of scheduling information are specific for shared downlinktransport channel while scheduling information of system informationblocks conveyed via broadcast transport channel is transmitted withinthe Master Information Block of the broadcast transport channel, that iswithin Layer 2 transport blocks. The configuration of the broadcasttransport channel may be for example semi-static, while theconfiguration of the shared downlink transport channel may besemi-static or dynamic. The flexibility of dynamic configuration of theshared transport channel in this embodiment of the invention may beadvantageous from radio resource utilization perspective since fastscheduling of broadcast system information could be efficientlysupported.

In an exemplary embodiment of the invention, the shared transportchannel may be the Shared Downlink CHannel (SDCH) of a UNITS system,while the broadcast transport channel may be the Broadcast CHannel(BCH); the control channel associated to the SDCH may be the SharedControl Signaling Channel (SCSCH).

FIG. 12 shows another exemplary mapping of system information blocks ofbroadcast system information to a broadcast transport channel and ashared transport channel using Layer 2 inband identification accordingto another embodiment of the invention.

In the exemplary embodiment illustrated in FIG. 12, a shared channel isused without the need of an associated (physical) control channel foridentification. As in the embodiment of the invention described withrespect to FIGS. 10 and 11, also in the embodiment shown in FIG. 12broadcast system information is mapped to a broadcast transport channeland a shared transport channel. The identifier (“ID) indicating thelogical channel-to-transport channel mapping and semi-staticconfiguration information (timing and transmission format) of the sharedchannel (e.g. SDCH) and configuration of associated physical controlchannel (e.g. SCSCH) are transmitted inband. This means that both piecesof information are transmitted at Layer 2. For example, theidentification (“ID”) may be provided within the header of Layer 2packets of the shared transport channel, while the configurationinformation of shared channel may be provided within MIB.

The identifier ID may be a default identifier or may beconfigured/assigned through MIB of the broadcast transport channel, asdescribed above. FIG. 13 shows an exemplary format of a MasterInformation Block used in the mapping of system information blocks inFIG. 12. The structure of the control information for SIBs mapped to thebroadcast transport channel is similar to that in the MIB shown in FIG.11. The MIB control information of the SIBs mapped to the sharedtransport channel may in addition comprise an indication of the sharedtransport channel to which they have been mapped respectively.

In the following paragraphs the mapping of the system information blockstransporting the individual portions of the broadcast system informationof the broadcast control logical channel according to differentembodiments will be described. In the following embodiments of theinvention described with respect to FIGS. 14 to 18, the broadcast systeminformation is transmitted in system information blocks that are mappedto a broadcast transport channel or a shared transport channel usingeither Layer 1 outband identification (FIGS. 10 and 11) or Layer 2inband identification (FIGS. 12 and 13). As will be explained in thefollowing, the mapping may be based for example on a property/propertiesinherent to a respective SIB or the mobile terminals to receive theSIBs.

FIGS. 8 and 9 show the transmission of broadcast information overbroadcast transport channel on a time axis. FIG. 8 is plotted forspectrum allocation of 5 MHz and broadcast data rate of 16 kbps. FIG. 9is plotted for spectrum allocation of 10 MHz and broadcast data rate of32 kbps.

In FIGS. 14 to 18, the spectrum allocation of either 5 MHz or 10 MHz isassumed and respective data rates of 16 or 32 kbps are (usuallyunevenly) distributed between broadcast and shared transport channel. Bymapping broadcast system information to broadcast and shared transportchannels a more flexible transmission scheme for broadcast systeminformation may be in comparison to cases where broadcast systeminformation is mapped only to a broadcast transport channel. Forexample, in FIG. 15 the data rate of broadcast and shared transportchannel is divided in ratio 3:1 since the resulting data rate on theshared channel is sufficient to transmit SIB1 over the shared transportchannel in one TTI, as will be explained below.

It should be noted that the actual resource utilization is not preciselyplotted in FIGS. 8, 9 and 14 to 18.

According to one embodiment of the invention, a criterion based on whichthe mapping of SIBs to either a shared transport channel or a broadcasttransport channel is decided, may be the importance of the informationof a respective SIB for mobile terminals.

Information important for mobile terminals may for example be systeminformation that is necessary to be received, stored and kept up-to-dateby mobile terminal in order to perform system access and elementarymobility procedures.

Considering for exemplary purposes only a UMTS system, system access maydesignate the procedure aimed at establishing signaling connection(signaling radio bearer). Hence, in this exemplary scenario theimportant information is information necessary for the mobile terminalto establish a signaling connection. Elementary mobility procedures onthe other hand designate the procedures aimed at tracking user locationby the network on tracking area level—without established signalingconnection—and on cell level—with established signaling connection.

Following the definition of important information and considering theexemplary classification of broadcast system information as shown inTable 5, SIB1, SIB2, SIB3, SIB5, SIB6, SIB17 and SIB18 may be classifiedas information important for mobile terminals, since they are necessaryfor performing system access and elementary mobility procedures. On theother hand, for example SIB13 and SIB15 may be classified as informationnot important (optional) for mobile terminals since they are notnecessary for performing system access and elementary mobilityprocedures.

FIG. 14 shows an exemplary mapping of system information blocks to ashared transport channel having a 5 MHz spectrum allocation and a datarate of 8 kbps and a broadcast control channel also having a 5 MHzspectrum allocation and a data rate of 8 kbps according to an embodimentof the invention. FIG. 14 proposes a mapping overcoming the problemsdiscussed with respect to FIG. 8, where the mobile terminal had toreceive two successive TTIs to obtain the important SIB8. In FIG. 14,SIB8 is now mapped to the shared transport channel, which allowstransmitting SIB8 in a single TTI, thereby reducing power consumption ofthe mobile terminal. Further, the MIB can be transmitted simultaneously(i.e. in the same TTI) as SIB8 which allows the mobile terminal toacquire the important information in SIB8 faster compared to thescenario in FIG. 8.

In the exemplary embodiment shown in FIG. 14, the mapping of SIB8 to theshared channel has been based on the importance of the informationcontained in SIB8 for the mobile terminals. Another criterion may be thesize of the SIBs. For example, SIBs larger than a predeterminedthreshold may be mapped to the shared transport channel. For example,this option may be of advantage, if several TTIs would be required forthe transmission of the SIB of broadcast transport channel and/or theshared transport channel can be sent with higher data rate than thatused for the broadcast transport channel.

FIG. 15 shows an exemplary mapping of system information blocks to ashared transport channel having a 10 MHz spectrum allocation and a datarate of 24 kbps and a broadcast control channel also having a 10 MHzspectrum allocation and a data rate of 8 kbps according to an embodimentof the invention. This exemplary embodiment illustrates an improvementof the system information allocation in FIG. 9, where SIB1 has been theonly SIB containing information relevant for the mobile terminal (theMIB may not be read every time it is transmitted). Though the mobileterminal may only be interested in the content of SIB1 of FIG. 9, itwould need to read the whole content broadcast on the broadcasttransport channel within a TTI, since receivers may typically only betuned to receive data within a whole TTI.

According to the embodiment illustrated in FIG. 15, the SIB(s)comprising information important for the mobile terminals are mapped tothe shared transport channel, while SIBs carrying optional information,i.e. information not important for the mobile terminals are mapped tothe broadcast transport channel. Assuming that the content of SIB2 andSIB3 in FIG. 15 is optional information and that the mobile terminal maynot need to read the MIB in this TTI, the mobile terminal may only readthe shared transport channel carrying SIB1 from the shared transportchannel and may save power by not reading the broadcast transportchannel in that TTI.

Further, considering that the data rates on shared transport channel andbroadcast transport channel may vary from each other, another benefit ofthe mapping of SIBs to a shared transport channel offering a lower datarate than the broadcast transport channel may be an increase in thereliability of the transmitted information in the SIBs transmitted onthe shared transport channel. Since a lower data rate may also imply alower coding rate and/or a lower order modulation scheme being usedcompared to the configuration of the broadcast control channel, theinformation transmitted via the shared transport channel may have ahigher reliability. In UMTS systems, the configuration of the broadcasttransport channel may be static and hence its data rate may not bechanged.

Another criterion that may be considered for mapping of SIBs to a sharedtransport channel or a broadcast transport channel may be the featuressupported by the mobile terminals within a certain cell. For example, ifnone of the mobile terminals currently present in a cell are supportingpositioning based on GPS (Global Positioning System), the related SIBmay be omitted from broadcast on the broadcast transport channel and maybe instead transmitted via a shared transport channel. Advantageously,the SIB may be transmitted during discontinuous reception (DRX) periodson the shared transport channel, if mobile terminals supporting GPSconnect/are handed over to the cell. Hence resources can be dynamicallyshared with user plane data.

FIG. 16 shows a mapping of SIBs to a shared or broadcast transportchannel based on the variability of the information in the respectiveSIB according to an embodiment of the invention. SIBs that comprisebroadcast system information of high variability may be mapped to theshared transport channel. Considering a classification of broadcastsystem information as shown in Table 5 above, e.g. physical channelconfiguration, interference and dynamic persistence level may beconsidered SIBs comprising information undergoing frequent changes.Further, as indicated above, depending on the data rate distributionbetween the broadcast transport channel and the shared transportchannel, the transmission of frequently changing SIBs via the sharedtransport channel may allow for lower repetition periods oralternatively increase the reliability of the transmission of therespective SIBs.

To generically classify information according to temporal variability,rates f1 and f2 (f1<f2) describing frequency of change of thisinformation may be considered. For example, an information (SIB) may beclassified to be of low temporal variability, if its rate of change frelates to f1 as f<=f1. Analogously, information may be of high temporalvariability, if its rate of change f relates to f2 as f>=f2. Finally,information is of medium temporal variability, if its rate of change frelates to f1 and f2 as f1<f<f2.

Another possible mapping of SIBs to a shared transport channel and abroadcast transport channel according to a further embodiment of theinvention is shown in FIG. 17. In this exemplary embodiment onlyoptional information (i.e. information not important for the mobileterminals) is mapped upon shared channel. The optional information mayfor example be ANSI 42 information or GPS information. This mapping maybe beneficial in that the mobile terminals would only need to acquirenecessary information from broadcast transport channel and withoutreading shared transport channel. Only if a mobile terminal wouldsupport a feature for which the optional information is needed, it mayread the respective SIBs from the shared transport channel.

In another embodiment of the invention, the configuration of sharedtransport channel used for the transmission of broadcast systeminformation in neighboring cells may be broadcast to the mobileterminals of a cell. Accordingly, FIG. 18 shows a mapping of systeminformation blocks of broadcast system information comprisinginformation on a shared transport channel in a neighboring radio cell toa broadcast transport channel and a shared transport channel and ahandover of a mobile terminal to the neighboring radio cell according toan embodiment of the invention. In the exemplary embodiment, it may beassumed that the shared transport channel in a respective cell is usedto provide system broadcast information to the mobile terminals that isimportant information, i.e. information necessary to perform systemaccess and elementary mobility procedures.

In FIG. 18, at the time instant n+1 (the time instants are given by thenumber of TTIs having past since a given starting time) the mobileterminal starts receiving the MIB via the broadcast transport channel.Further it may be assumed that SIB8 in each radio cell comprisesinformation necessary to perform system access and elementary mobilityprocedures. The dashed blocks are intended to indicate, that the mobileterminal receiving the information is located in a source cell, whenreceiving the information. The MIB received in the TTI following timeinstant n+1 may comprise an indication to the shared transport channelat which SIB8 is broadcast in a neighboring cell(s). Alternatively, aSIB containing this information may be specified by the MIB (for exampleSIB3 read by the mobile terminal at the TTI starting at time instant n).

Upon the time instant n+2, the mobile terminal is handed over from itssource cell to another cell, the target cell. Since it has alreadyacquired the control information necessary to receive SIB8 on the sharedtransport channel, the mobile terminal may already read SIB8 from theshared transport channel of the target cell at time instant n+2. Hence,the mobile terminal may not need to receive the first MIB in the targetcell transmitted at time instant n+3 on the broadcast transport channelto be able to read SIB8 from the shared transport channel at timeinstant n+4.

More generally, information on the configuration of the neighboringcells (including the target cell) may be provided as part of thebroadcast system information within a cell. The configurationinformation on the neighboring cells may be for example included in asystem information block or may be provided as part of the MIB to themobile terminals of a radio cell. The configuration information maydepend on the respective mapping used for transmission of the broadcastsystem information via the shared transport channel and the broadcasttransport channel in a respective neighboring cell.

If a configuration as shown in FIG. 10 is used, the MIB may comprisechunk allocation and possibly modulation format, transport block sizeetc. of the control physical channel associated to the shared transportchannel in the neighboring cell(s). The associated physical controlchannel in the neighboring cell then contains chunk allocation,modulation format, transport block size etc. for the shared transportchannel in the neighboring cell. This information may be changed on adynamic basis in the neighboring cell.

Alternatively, when using a configuration as shown in FIG. 12, the MIBin the source cell may comprise chunk allocation, modulation format,transport block size etc. for the shared transport channel in theneighboring cell(s). This information may for example be changed onsemi-static basis in the neighboring cell.

In FIGS. 10 to 18 illustrating various exemplary embodiments of theinvention, the different SIBs have been distinguished by differentnumbers (SIB1, SIB2, SIB3, etc.). These numbers are merely intended toexemplarily indicate different information comprised by the respectiveSIB. However, in another embodiment of the invention the numbering ofSIBs may indicate their respective content as indicated e.g. in Table 5.

Another embodiment of the invention relates to the implementation of theabove described various embodiments using hardware and software. It isrecognized that the various embodiments of the invention above may beimplemented or performed using computing devices (processors). Acomputing device or processor may for example be general purposeprocessors, digital signal processors (DSP), application specificintegrated circuits (ASIC), field programmable gate arrays (FPGA) orother programmable logic devices, etc. The various embodiments of theinvention may also be performed or embodied by a combination of thesedevices.

Further, the various embodiments of the invention may also beimplemented by means of software modules, which are executed by aprocessor or directly in hardware. Also a combination of softwaremodules and a hardware implementation may be possible. The softwaremodules may be stored on any kind of computer readable storage media,for example RAM, EPROM, EEPROM, flash memory, registers, hard disks,CD-ROM, DVD, etc.

What is claimed is:
 1. A mobile terminal for receiving broadcast systeminformation in a radio access network of a mobile communication system,the mobile terminal comprising: a receiver and a processor, theprocessor and receiver being configured to: receive, by the receiver, amaster information block of a broadcast control logical channel via abroadcast transport channel; obtain, by the processor, timinginformation from the master information block; receive, by the receiver,control information on a control channel associated to a sharedtransport channel; determine from the control information, by theprocessor, a modulation parameter for a system information block that ismapped on the shared transport channel that uses dynamically allocatedresources; and receive, by the receiver, the system information blockvia the shared transport channel according to the timing information andthe modulation parameter.
 2. A mobile terminal as claimed in claim 1,wherein, the master information block is received periodically.
 3. Amobile terminal as claimed in claim 2, wherein, the master informationblock is received at the beginning of each transport block.
 4. A mobileterminal as claimed in claim 2, wherein, the master information block isreceived after a predetermined time span, whereby the predetermined timespan is a given number of transmission time intervals.
 5. A mobileterminal as claimed in claim 1, wherein, the control information furthercomprises transmission format information regarding the systeminformation block that is mapped on the shared transport channel.
 6. Amobile terminal as claimed in claim 1, wherein, the control channel is aphysical downlink control channel (PDCCH).
 7. A method of receivingbroadcast system information in a radio access network of a mobilecommunication system comprising: using a mobile terminal comprising areceiver and a processor to: receive by the receiver, a masterinformation block of a broadcast control logical channel via a broadcasttransport channel; obtain, by the processor, timing information from themaster information block; receive, by the receiver, control informationon a control channel associated to a shared transport channel; determinefrom the control information, by the processor, a modulation parameterfor a system information block that is mapped on the shared transportchannel that uses dynamically allocated resources; and receive, by thereceiver, the system information block via the shared transport channelaccording to the timing information and the modulation parameter.
 8. Amethod of receiving broadcast system information as claimed in claim 7,wherein, the master information block is received periodically.
 9. Amethod of receiving broadcast system information as claimed in claim 8,wherein, the master information block is received at the beginning ofeach transport block.
 10. A method of receiving broadcast systeminformation as claimed in claim 8, wherein, the master information blockis received after a predetermined time span, whereby the predeterminedtime span is a given number of transmission time intervals.
 11. A methodof receiving broadcast system information as claimed in claim 7,wherein, the control information further comprises transmission formatinformation regarding the system information block that is mapped on theshared transport channel.
 12. A method of receiving broadcast systeminformation as claimed in claim 7, wherein, the control channel is aphysical downlink control channel (PDCCH).
 13. A transmitting apparatusfor transmitting broadcast system information in a radio access networkof a mobile communication system, the transmitting apparatus comprising:a transmitter and a processor, the processor and transmitter beingconfigured to: transmit, by the transmitter, a master information blockof a broadcast control logical channel via a broadcast transportchannel; include, by the processor, timing information in the masterinformation block; transmit, by the transmitter, control information ona control channel associated to a shared transport channel; include inthe control information, by the processor, a modulation parameter for asystem information block that is mapped on the shared transport channelthat uses dynamically allocated resources; and transmit, by thetransmitter, the system information block via the shared transportchannel according to the timing information and the modulationparameter.
 14. A transmitting apparatus as claimed in claim 13, wherein,the master information block is transmitted periodically.
 15. Atransmitting apparatus as claimed in claim 14, wherein, the masterinformation block is transmitted at the beginning of each transportblock.
 16. A transmitting apparatus as claimed in claim 14, wherein, themaster information block is transmitted after a predetermined time span,whereby the predetermined time span is a given number of transmissiontime intervals.
 17. A transmitting apparatus as claimed in claim 13,wherein, the control information further comprises transmission formatinformation regarding the system information block that is mapped on theshared transport channel.
 18. A transmitting apparatus as claimed inclaim 13, wherein, the control channel is a physical downlink controlchannel (PDCCH).